This invention relates to apparatus for use in preparation of coke from crude petroleum products.
A "delay coker" is an apparatus for the preparation of coke from the heaviest portion of crude oil (commonly referred to as "bunker" fuel). The crude is generally heated to a temperature of about 800.degree.-900.degree. C. and then fed into the bottom of a coke drum. The coke drum has a diameter on the order of 25 feet and may be 80-90 feet high. At an elevated pressure (e.g., 30 pounds or more), the heated crude is thermally decomposed to leave a coke residue. During the thermal decomposition, lighter products such as hydrocarbons gases, gasoline and jet fuel, are recovered from the top of the coke drum. The decomposition process takes on the order of 16-20 hours to complete.
The solid residue is treated with steam to remove any entrained volatile hydrocarbons. The residue is then cooled down with water. Finally, the coke drum is opened at both the top and the bottom, and the solid product is drilled out for recovery. A typical drilling procedure employs a high pressure water drill (for example, using 3000 lb/in.sup.2 pressure).
The heavy crude which is treated in the coke drum is supplied to the drum by means of a feed line. This line from the crude source is directly connected to a feed inlet, usually in the bottom lid of the coke drum. Generally, both the feed line and the feed inlet terminate in flanges; the respective flanges are designed to achieve a mutual engagement when the feed line and feed inlet are brought into contact.
When it is desired to open both ends of the coke drum in order to remove the accumulated coke, it is generally first necessary to disconnect the feed line from the feed inlet. As the feed line is a conduit of fairly significant diameter (at least 10") and may have a significant length, manual connection and disconnection of the feed line with the feed inlet is a burdensome task. Moreover, because the coke drum is still at a fairly elevated temperature at the time the line is to be disconnected, operator contact with the apparatus is not desirable. The feed line is also at an elevated temperature, due to the presence of the heated crude therein. Further, even after steam treatment there may be hydrocarbon vapors released when the feed line is disconnected from the feed inlet. It would be preferable if the likelihood of operator exposure to such hydrocarbon vapors and/or steam were reduced or eliminated.
Accordingly, it is an object of the present invention to provide methods and apparatus for moving a feed line relative to an associated feed inlet, whereby direct operator contact with the apparatus is minimized and physical effort is reduced.